CN1448756A - Polarized light converting device, lighting optical device and projector - Google Patents

Abstract

Contains: polarized light separation films 511 that separate incident light into two types of linearly polarized light; reflective films 512 that are alternately arranged between the polarized light separation films 511 and reflect linearly polarized light reflected by the polarized light separation films 511; The plate glass 513 of the light separation film 511 and the reflection film 512 ; At a position where the light beam incident side of the polarization conversion element main body 414B is not opposed to the phase difference plate 600, a fixed frame 414A for blocking the incident light beam is provided. The fixed frame 414A has a holding portion for holding the end face of the polarization conversion element main body 414B, and Fixing part for fixing on the light guide body.

Description

Polarized light conversion device, illumination optical device and projector

technical field

The present invention relates to a polarization conversion device, an illumination optical device including the polarization conversion device, and a projector.

Background technique

Conventionally, projectors have been frequently used for presentations at conferences, conferences, exhibitions, and the like. In such a projector, a plurality of optical components are accommodated in a casing for optical components, and a light beam emitted from a light source is modulated via these optical components, and then enlarged and projected to form a projected image. As such an optical component, in order to improve the utilization efficiency of the light beam and ensure a bright projected image, a polarization conversion device that converts the light beam emitted from the light source into one type of linearly polarized light is used.

The configuration of the polarized light conversion device includes: a polarized light separation film arranged obliquely with respect to the incident light beam, which divides the light beam from the light source into two types of linearly polarized light; a reflection film which reflects the linearly polarized light separated by the polarized light separation film; Between these polarized light separation films and reflective films, a polarized light conversion element that alternately arranges a plurality of polarized light separation films and reflective films as transmissive members; , a phase difference plate for converting the polarization axis of the light beam emitted from the reflective film; and a light-shielding mask arranged on the light beam incident side of the polarization conversion element to block the light beam incident on the reflective film.

Such a polarization conversion device is a unit composed of three components: a polarization conversion element main body including a retardation plate and a polarization conversion element, a light-shielding mask, and a holding frame for holding and accommodating the polarization conversion element main body and the light-shielding mask. The configuration is to house each unit in a case for optical components.

However, in this case, in the holding frame, it is necessary to adjust the position of the holding frame and the housing for optical parts as well as the relative position adjustment of the main body of the polarization conversion element and the light-shielding mask. The installation work in the parts box becomes complicated. In addition, in order to simplify the mounting work, it is also considered to increase the opening area ratio of the light-shielding mask, but in this case, it is meaningless because the original function of light-shielding function is reduced.

Contents of the invention

The object of the present invention is to provide a polarization conversion device which can reduce the number of components and facilitate the relative position adjustment of the light shielding part and the polarization conversion element main body in the box for optical parts, and has the polarization conversion device lighting optics, and projectors.

The polarization conversion device of the present invention is characterized in that it has a polarization conversion element main body and a light-shielding member, wherein the configuration of the polarization conversion element includes: being arranged obliquely with respect to an incident light beam, and separating the incident light beam into two types of linearly polarized light A plurality of polarized light separation films for light beams are alternately arranged side by side between each polarized light separation film, and a plurality of reflective films that reflect any one of the polarized light beams separated on the above-mentioned polarized light separation film are provided with these polarized light separation films. A transmissive member of a film and a reflective film, and a plurality of retardation plates that are arranged on the beam emitting side of the transmissive member to convert the polarization axis of any one of the above-mentioned polarized light beams; the light shielding member is provided In a position not facing the above-mentioned retardation plate on the light-beam incident side of the above-mentioned transmissive member, the incidence of the light beam emitted from the above-mentioned light source is blocked, and the light-shielding member has a holding part for holding the end face of the above-mentioned polarization conversion element main body, and a fixing part for attaching to an optical component case housing the polarization conversion element.

In the present invention, for example, the main body of the polarization conversion element and the light-shielding member are constructed based on an outer shape such that the mask for light shielding is located at a position corresponding to each component of the main body of the polarization conversion element, and then the The polarization conversion device is formed by holding the main body of the polarization conversion element on the holding part of the light shielding member, and the polarization conversion device is attached to the optical component case through the fixing part.

Therefore, if the present invention is adopted, since the main body of the polarization conversion element is held by the holding portion of the light-shielding member, and it is housed in the case for optical parts in this holding state, the number of components of the polarization conversion device can be further reduced than before. The position of the light-shielding mask of the light-shielding member at a predetermined position relative to the main body of the polarization conversion element can be adjusted with high precision while reducing the number of parts. Since the position adjustment can be performed with high precision, the shielding property of unnecessary light can be improved, and the light beam from the light source can be used more effectively.

In the above polarized light conversion device, preferably, the fixing portion is an extension portion extending outward along the holding surface of the holding portion from both ends of the end portion of the holding portion that is in contact with the housing for optical components. The extending portion is formed with an insertion opening through which the protrusion formed on the optical component housing is inserted.

In this case, for example, the following configurations can be provided.

That is, in the light-shielding member, the holding frame constituting the frame-shaped holding portion holding the plate-shaped polarization conversion element main body is formed, and an extension portion extending outward from the lower end portion of the holding frame along the holding frame surface is formed. A circular opening is formed on the extension. On the other hand, a protrusion capable of being inserted into the circular opening is formed on the lower portion of the optical component case. The polarization conversion device is attached to the optical component case by inserting protrusions through these circular openings. Such components having a relatively simple structure can specifically constitute the polarization conversion device without increasing the manufacturing cost of the polarization conversion device.

The above-mentioned light shielding member is preferably formed of a metal material.

In this case, by providing the light shielding member made of metal, sufficient rigidity can be ensured as a member for holding the main body of the polarization conversion element. In addition, since it is made of metal with high thermal conductivity, heat generated in the polarization conversion element main body can be dissipated to the outside, and thermal damage to the heat-resistant polarization conversion element main body can be prevented.

In the above polarized light conversion device, preferably, the polarized light separating films and the reflective films are arranged alternately at predetermined intervals with an inclination of approximately 45° with respect to the light beam incident direction.

In this case, since the polarized light separation film and the reflective film are inclined approximately 45° relative to the beam incident direction, and are alternately arranged at predetermined intervals, the polarization axis of the generated and required linearly polarized light can not be increased excessively. Different invalid regions of linearly polarized light make the main body of the polarization conversion element under optimal conditions.

The illumination optical device of the present invention is characterized by comprising a light source, a light beam splitting element for splitting a light beam from the light source into a plurality of regions, and the above-mentioned polarization conversion device.

According to the present invention, substantially the same effect as that of the above-mentioned polarized light conversion device can be achieved, whereby the light beam emitted from the illumination optical device can be converted into approximately one kind of linearly polarized light, and the effective use of the light beam can be realized.

A projector according to the present invention is characterized by comprising: the above-mentioned illumination optical device, a light modulation device for modulating a light beam emitted from the illumination optical device according to graphic information, and a projection optical device for enlarging and projecting the light beam modulated by the light modulation device.

According to the present invention, substantially the same effect as that of the above-mentioned polarized light conversion device can be achieved, and therefore, effective use of light beams can be realized, and a projected image projected from a projector can be clearly displayed. In addition, as described above, since the effective use of light beams can be realized, it is possible to reduce the absorption of unnecessary light on the incident-side polarizing plate arranged on the incident side of the light modulation device, and prevent the Heat loss from the polarizer.

Description of drawings

FIG. 1 is an overall perspective view of a projector according to an embodiment of the present invention seen from the upper front.

Fig. 2 is an overall perspective view of the projector viewed from the lower rear.

FIG. 3 is a perspective view showing the interior of the above projector. Specifically, it is a figure in which the upper case of the projector is removed from the state shown in FIG. 1 .

FIG. 4 is a perspective view showing the inside of the projector described above. Specifically, it is a view in which the control board is removed from the state shown in FIG. 3 .

Fig. 5 is an exploded perspective view showing the optical unit.

FIG. 6 is a diagram schematically showing the above-mentioned optical unit.

Fig. 7 is a perspective view of the optical device main body seen from the lower side.

FIG. 8 is a diagram illustrating the flow of cooling air in the panel cooling system A and the power supply cooling system C in the above embodiment.

FIG. 9 is a diagram illustrating the flow of cooling air in the panel cooling system A and the polarization conversion element cooling system B in the above embodiment.

Fig. 10 is a perspective view showing a polarization conversion device of the present invention.

FIG. 11 is a diagram showing a state in which the above-mentioned polarization conversion device is housed in a light guide.

Fig. 12 is an exploded perspective view showing the above-mentioned polarization conversion device.

Fig. 13 is a diagram for explaining the manufacture of the polarization conversion element array, and is a schematic diagram viewed from the thickness dimension direction.

Fig. 14 is a schematic diagram of a part of the main body of the above-mentioned polarization conversion element viewed from above.

Fig. 15 is a perspective view of the above fixed frame viewed from the beam incident side.

Fig. 16 is a perspective view showing a state in which the polarization conversion device is housed in the light guide.

FIG. 17 is a schematic diagram for explaining the function of the above-mentioned polarization conversion device.

Detailed ways

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

1. The main body of the projector

FIG. 1 is a perspective view of a projector 1 of the present invention seen from the upper front. FIG. 2 is a perspective view of the projector 1 viewed from the lower back.

As shown in FIG. 1 or FIG. 2 , a projector 1 has a substantially rectangular parallelepiped housing 2 formed by injection molding. The case 2 is a case made of synthetic resin that accommodates the main body of the projector 1, and has an upper case 21 and a lower case 22, and these cases 21, 22 are mutually detachable.

The upper case 21, as shown in FIGS. 1 and 2 , includes an upper portion 21A, a side portion 21B, a front portion 21C, and a rear portion 21D that constitute the top, side, front, and rear sides of the projector 1, respectively.

Similarly, the lower case 22, also shown in FIGS.

Thus, as shown in FIGS. 1 and 2, in the rectangular parallelepiped shell 2, the side portions 210 forming a cuboid are continuously connected between the side portions 21B, 22B of the upper case 21 and the lower case 22. Similarly, through the front portions 21C, 22C The connection between them constitutes the front part 220, the connection between the back parts 21D and 22D constitutes the back part 230, the upper part 21A constitutes the upper part 240, and the lower part 22A constitutes the lower part 250.

As shown in FIG. 1 , an operation panel 23 is provided on the front side of the upper surface portion 240 , and a speaker hole 240A for sound output is formed in the vicinity of the operation panel 23 .

In the side part 210 on the right side viewed from the front, an opening 211 spanning the two side parts 21B and 22B is formed. Here, in the case 2, a main board 51 and an interface board 52 to be described later are provided, and the connection portion 51B mounted on the main board 51 is mounted on the interface board via the interface panel 53 mounted on the opening 211 . The connecting portion 52A on the 52 is exposed to the outside. External electronic devices and the like are connected to the projector 1 at these connection portions 51B and 52A.

In the front portion 220 , a circular opening 221 spanning the two front portions 21C, 22C is formed in the vicinity of the operation panel 23 on the right side as viewed from the front. A projection lens 46 is disposed inside the casing 2 so as to correspond to the opening 221 . At this time, the front end portion of the projection lens 46 is exposed to the outside through the opening 221 , and the focusing operation of the projection lens 46 can be performed manually via the rod 46A that is a part of the exposed portion.

On the front portion 220 , an exhaust port 222 is formed at a position on the opposite side of the opening 221 . A safety cover 222A is formed on the exhaust port 222 .

As shown in FIG. 2 , on the rear portion 230 , a rectangular opening 231 from which the access connector 24 is exposed is formed on the right side as viewed from the rear.

In the lower portion 250, a rectangular opening 251 is formed at a central position on the right end side as viewed from below. The opening 251 is provided with a lamp cover 25 that covers the opening 251 and is detachable. By removing the lamp cover 25, the light source lamp (not shown) can be easily replaced.

In addition, on the lower surface portion 250, a rectangular surface 252 recessed inward is formed at the corner portion on the left side when viewed from below. On this rectangular surface 252, an air intake port 252A for inhaling cooling air from the outside is formed. On the rectangular surface 252, the suction port cover 26 which covers this rectangular surface 252 is provided in a detachable manner. An opening 26A corresponding to the intake port 252A is formed in the intake port cover 26 . An unillustrated air filter is provided on the opening 26A to prevent dust from entering the inside.

Further, rear legs 2R constituting the legs of the projector 1 are formed at the substantially central position on the rear side of the lower surface portion 250 . In addition, front legs 2F that also constitute the legs of the projector 1 are respectively provided on the left and right corners on the front side of the lower surface portion 250 . That is, the projector 1 is supported by three points of the rear leg 2R and the two front legs 2F.

The two front legs 2F can move forward and backward in the vertical direction respectively, and can adjust the inclination (posture) of the projector 1 in the front-back direction and the left-right direction, so as to adjust the position of the projected image.

In addition, as shown in FIGS. 1 and 2 , a rectangular parallelepiped concave portion 253 is formed at a substantially central position on the front side of the housing 2 so as to straddle the lower portion 250 and the front portion 220 . The recessed portion 253 is provided with a cover member 27 that is slidable in the front-rear direction and covers the lower side and the front side of the recessed portion 253 . The cover member 27 accommodates a remote controller (not shown) for remote control of the projector 1 in the concave portion 253 .

Here, FIGS. 3 and 4 are perspective views showing the interior of the projector 1 . Specifically, FIG. 3 is a diagram in which the upper case 21 of the projector 1 is removed from the state shown in FIG. 1 . FIG. 4 is a diagram showing the control board 5 removed from the state shown in FIG. 3 .

In the case 2, as shown in FIGS. 3 and 4 , there is: a power supply unit 3 arranged along the back portion and extending in the left-right direction; The optical unit 4; the control substrate 5 as a control part arranged above and on the right side of these units 3, 4. These devices 3 to 5 constitute the main body of the projector.

The configuration of the power supply unit 3 includes a power supply 31 and an unillustrated lamp driving circuit (ballast) arranged under the power supply 31 .

The power supply 31 supplies electric power supplied from the outside through a power supply cable (not shown) connected to the power supply interface, to the lamp driving circuit, the control board 5 and the like.

The above-mentioned lamp driving circuit supplies electric power supplied from the power supply 31 to a light source lamp not shown in FIGS. 3 and 4 constituting the optical unit 4, and is electrically connected to the above-mentioned light source lamp. Such a lamp driving circuit can be constituted, for example, by wiring on a substrate.

The power supply 31 and the above-mentioned lamp driving circuit are arranged vertically and substantially parallel to each other, and the space occupied by them extends in the left-right direction on the rear side of the projector 1 .

In addition, the power supply 31 and the above-mentioned lamp driving circuit are surrounded by shield members 31A made of metal such as aluminum that are opened on the left and right sides.

The shielding member 31A has a function of preventing electromagnetic interference generated by the power supply 31 and the above-mentioned lamp driving circuit from leaking to the outside, in addition to the function as a passage for guiding cooling air.

Control board 5, as shown in FIG. interface panel 52 .

In this control board 5 , the CPU and the like of the main board 51 perform control of a liquid crystal panel constituting an optical device described later based on image information input through the connection parts 51B and 52A.

The main substrate 51 is surrounded by a metallic shield member 51A. The main substrate 51 is in contact with an upper end portion 472A ( FIG. 4 ) of an upper light guide 472 constituting the optical unit 4 , although it is difficult to see in FIG. 3 .

2. Detailed composition of the optical unit

Here, FIG. 5 is an exploded perspective view showing the optical unit 4 . FIG. 6 is a diagram schematically showing the optical unit 4 .

The optical unit 4, as shown in FIG. 6 , is a unit that optically processes the light beam emitted from the light source lamp 416 constituting the light source device 411 to form an optical image corresponding to the image information, and enlarges and projects the optical image. It has an integrator illumination optical system 41 , a color separation optical system 42, a relay optical system 43, an optical device 44, a projection lens 46, and a synthetic resin light guide 47 (FIG. 5) housing these optical components 41-44, 46.

The integrator illumination optical system 41 is for substantially uniformly illuminating the image forming regions of the three liquid crystal panels 441 (the liquid crystal panels 441R, 441G, and 441B are respectively provided for each color light of red, green, and blue) constituting the optical device 44. The optical system includes a light source device 411 , a first lens array 412 , a second lens array 413 , a polarization conversion device 414 , and a superposition lens 415 .

The light source device 411 has a light source lamp 416 as an emission light source and a reflector 417, reflects the radial light rays emitted from the light source lamp 416 by the reflector 417 to form parallel light, and emits the parallel light to the outside. The light source lamp 416 is a high pressure mercury lamp. Furthermore, in addition to high-pressure mercury lamps, metal halide lamps, halogen lamps, and the like can be used. In addition, the reflector 417 adopts a parabolic mirror. Furthermore, instead of a parabolic mirror, a combination of a parallelized concave lens and an elliptical mirror may also be used.

The first lens array 412 has a configuration in which small lenses having a substantially rectangular outline viewed from the optical axis direction are arranged in a matrix shape. Each small lens divides the light beam emitted from the light source lamp 416 into a plurality of partial light beams. The contour shape of each small lens is set to be substantially similar to the shape of the image forming region of the liquid crystal panel 441 . For example, if the aspect ratio (ratio of horizontal and vertical dimensions) of the image forming region of the liquid crystal panel 441 is 4:3, the aspect ratio of each small lens is also set to 4:3.

The second lens array 413 has substantially the same configuration as the first lens array 412, and has a configuration in which small lenses are arranged in a matrix. The second lens array 413 has a function of imaging the images of the small lenses of the first lens array 412 on the liquid crystal panel 441 together with the overlapping lens 415 .

The polarization conversion device 414 is arranged between the second lens array 413 and the overlapping lens 415 . Such a polarization converting device 414 can convert the light from the second lens 413 into substantially one kind of polarized light, thereby improving the utilization efficiency of light in the optical device 44 .

Specifically, each partial light converted into one type of polarized light by the polarization conversion device 414 is finally substantially superimposed on the liquid crystal panel 441 of the optical device 44 by the superimposing lens 415 . In the projector 1 using the polarized modulation type liquid crystal panel 441, only one type of polarized light can be used, so almost half of the light beams emitted from the light source lamp 416 emitting other random polarized lights cannot be used. Therefore, by using the polarization conversion device 414 to convert all the light beams emitted from the light source device 416 into approximately one type of polarized light, the utilization efficiency of light in the optical device 44 can be improved. Furthermore, the detailed structure of the polarization conversion device 414 will be described later.

The color separation optical system 42 has 2 dichroic reflectors 421, 422, and a reflector 423, which is used to separate the multi-part light beams emitted from the integrator illumination optical system 41 into red (R) with the dichroic reflectors 421, 422. , green (G), blue (B) 3 kinds of color light function.

The relay optical system 43 has an incident side lens 431, a relay lens 433, and mirrors 432 and 434, and has a function of guiding red light among the color lights separated by the color separation optical system 42 to the liquid crystal panel 441R.

At this time, the dichroic mirror 421 of the color separation optical system 42 transmits the red light component and the green light component and reflects the blue light component in the light beam emitted from the integrator illumination optical system 41 . The blue light reflected by the dichroic mirror 421 is then reflected by the mirror 423, passes through the field lens 418, and reaches the blue liquid crystal panel 441B. The field lens 418 transforms each partial light beam emitted from the lens array 413 into a parallel light beam with respect to its central axis (chief ray). The same applies to the field lenses 418 provided on the light-incident sides of the other liquid crystal panels 441G and 441R.

In addition, among the red light and the green light transmitted through the dichroic mirror 421 , the green light is reflected by the dichroic mirror 422 , passes through the field lens 418 , and reaches the liquid crystal panel 441G for green. On the other hand, the red light passes through the dichroic mirror 422 , passes through the relay optical system 43 , and then passes through the field lens 418 to reach the liquid crystal panel 441R for red light.

Furthermore, the reason why the relay optical system 43 is used for red light is because the length of the optical path of red light is longer than that of other colors of light, so that the reason for preventing light utilization efficiency from decreasing due to light divergence and the like. That is, it is because the partial light beam incident on the incident-side lens 431 is directly transmitted to the field lens 418 . Furthermore, although the relay optical system 43 is configured to pass red light among the three kinds of color light, the present invention is not limited thereto. For example, blue light may be passed.

The optical device 44 is a device that modulates incident light beams according to image information to form a color image, and has: three incident-side polarizing plates 442 that are incident on each color light separated by the color separation optical system 42; Liquid crystal panels 441R, 441G, and 441B of the light modulation device on the rear stage of 442; exit-side polarizing plates 443 disposed on the rear stages of the respective liquid crystal panels 441R, 441G, and 441B; cross dichroic prisms 444 as a composite optical system .

The liquid crystal panels 441R, 441G, and 441B are, for example, liquid crystal panels using polysilicon TFTs as switching elements.

In the optical device 44, the color lights separated by the color separation optical system 42 are modulated by the three liquid crystal panels 441R, 441G, 441B, the incident side polarizer 442, and the output polarizer 443 according to the image information to form an optical image.

The incident side polarizing plate 442 transmits only the polarized light in a certain direction and absorbs other light beams among the color lights separated by the color separation optical system 42, and is a polarizing plate with a polarizing film attached to a substrate such as sapphire glass. . In addition, instead of using a substrate, a polarizing film may be attached to the field lens 418 .

The output-side polarizing plate 443 also has substantially the same configuration as the incident-side polarizing plate 442, and transmits only polarized light in a certain direction among the light beams emitted from the liquid crystal panel 441 (441R, 441G, 441B) and absorbs other light beams. Alternatively, the polarizing film may be attached to the cross dichroic prism 444 without using a substrate.

The incident-side polarizing plate 442 and the output-side polarizing plate 443 are set so that the directions of their polarization axes are perpendicular to each other.

The cross dichroic prism 444 is a prism that synthesizes optical images emitted from the output-side polarizing plate 443 and modulated for each color light to form a color image.

On the cross dichroic prism 444, a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are arranged in an approximately X shape along the interfaces of the four right-angle prisms, and three dielectric multilayer films are synthesized with these dielectric multilayer films. color light.

The above-mentioned liquid crystal panel 441 , exit-side polarizing plate 443 , and cross dichroic prism 444 constitute an optical device main body 45 that is integrally united. FIG. 7 is a perspective view showing the optical device main body 45 .

Optical device main body 45, as shown in FIG. The metal holding plate 446 holding the output side polarizing plate 443; the liquid crystal panel 441 (441R, 441G, 441B).

Between the holding plate 446 and the liquid crystal panel 441, a gap is provided at a predetermined interval, and cooling air flows through the gap.

The optical device main body 45 is screwed to the lower light guide body 471 through the round holes 447B formed in the four arm portions 447A of the fixing plate 447 .

The projection lens 46 is a lens for enlarging and projecting the color image synthesized by the cross dichroic prism 444 of the optical device 44 .

The light guide body 47, as shown in FIG. 5 , comprises: a lower light guide body formed with grooves for slidingly fitting the optical parts 412 to 415, 418, 421 to 423, 431 to 434, and 442 from above. 471 . Cover-shaped upper light guide 472 blocking the upper opening of the lower light guide 471 .

As shown in FIG. 5 , the light source device 411 is accommodated at one end side of the substantially L-shaped lower light guide body 471 in plan view. On the other end side, via a head portion 473 formed on the lower light guide body 471 , the projection lens 46 is screwed.

In addition, as shown in FIG. 5 , the optical device main body 45 housed in the lower light guide body 471 is screwed to the lower light guide body 471 with the two spring members 50 interposed therebetween. These two spring members 50 bias (load) the field lens 418 and the incident-side polarizing plate downward to fix their positions.

3. Cooling structure

FIG. 8 is a view in which the above-mentioned upper light guide body and optical device main body 45 are removed from FIG. 4 . In addition, FIG. 9 is a perspective view showing the optical unit 4 .

Here, in the projector 1, as shown in FIGS. 3, and the light source cooling system D that mainly cools the light source device 411.

As shown in FIG. 8 , in the panel cooling system A, a large sirocco fan 61 provided on the lower side of the power supply unit 3 is used.

In the panel cooling system A, as shown in FIG. 8 or 9, the external cooling air sucked in from the suction port 252A ( FIG. 2 ) formed on the lower part 250 of the housing 2 by the Sirocco fan 61 is used, not shown in the figure. The channels are guided below the main body 45 of the optical device, and enter into the interior of the light guide body 47 from the suction ports formed on the lower sides of the liquid crystal panels 441 formed on the lower light guide body 471 . This cooling air, as shown in FIG. 9 , passes through the gap between each liquid crystal panel 441R, 441G, 441B and the cross dichroic prism 444, cools the liquid crystal panel 441 and the above-mentioned exit side polarizing plate, and is then discharged to the upper light guide 472. and the space between the above control substrate. In addition, the cooling air passes through the gaps between the liquid crystal panels 441R, 441G, 441B and the field lens 418, cools the liquid crystal panel 441 and the above-mentioned incident-side polarizing plate, and is then discharged to the above-mentioned light guide body 472 and the above-mentioned incident-side polarizing plate. between.

Furthermore, the air exhausted into this space cannot flow toward the projection lens 46 side due to the contact between the upper end portion 472A of the upper light guide body 472 and the above-mentioned control substrate 5 .

In the polarization conversion element cooling system B, the cooling air sucked by the sirocco fan 61 is guided to the lower side of the polarization conversion device 414 through a passage not shown in the figure arranged on the lower side of the lower light guide body 471, Enter the light guide body 47 from the suction port on the lower side of the polarized light conversion device 414 formed on the lower light guide body 471, after cooling the polarized light conversion device 414, from the discharge port formed on the upper light guide body 472 474 discharge.

In the power supply cooling system C, as shown in FIG. 8 , a small sirocco fan 62 arranged on the upper side of the sirocco fan 61 with a metal plate interposed therebetween is used.

In the power supply cooling system C, the cooling air flowing between the upper light guide body 472 and the above-mentioned control board 5 through the panel cooling system A is sucked by the sirocco fan 62 while cooling the control board 5, and is discharged into the inside of the power supply unit 3 side. The air discharged into the interior flows along the shield member 31A to cool the power supply 31 and the above-mentioned lamp driving circuit, and is discharged from an opening opposite to the sirocco fan 62 .

In this cooling system D, an axial fan 63 arranged on the front side of the light source device 411 and a duct 64 attached to the axial fan 63 are used.

In the light source cooling system D, the air discharged from the power supply cooling system C and the polarization conversion element cooling system B is sucked by the axial flow fan 63, and enters the light source device from the slit-shaped opening formed on the side part of the light source device 411. The light source lamp 416 is cooled in 411 , and is exhausted from the exhaust port 222 of the housing 2 to the outside through the channel 64 .

4. Structure of polarized light conversion device

Fig. 10 is a perspective view showing a polarization conversion device. Fig. 11 is a diagram showing a state in which the polarization conversion device is housed in the light guide. Fig. 12 is an exploded perspective view showing a polarization conversion device.

The polarized light conversion device 414, as described above, is a device for converting the light beam converged by each small lens of the second lens array 413 into approximately one kind of polarized light when it is transmitted. The polarized light conversion device 414 is shown in FIG. 10 , It includes: a flat plate-shaped polarization conversion element main body 414B; and a fixing frame 414A as a frame-shaped light-shielding member adhesively fixed to the polarization conversion element main body 414B. The polarization conversion element main body 414B and the fixing frame 414A are bonded and fixed with an adhesive.

In addition, as shown in FIG. 11 , the polarization conversion device 414 is accommodated in the lower light guide body 471 constituting the light guide body 46 . In this case, the fixing frame 414A is arranged on the light source lamp side, that is, the light beam incident side, and the polarization conversion element main body 414B is arranged on the light beam emitting side.

The polarization conversion element main body 414B includes, as shown in FIG. 12 , a flat polarization conversion element array 500 and a retardation plate 600 disposed on the light beam output side of the polarization conversion element array 500 . The polarization conversion element main body 414B is separated into two types of linearly polarized light by the polarization conversion element array 500, and in the phase difference plate 600, the polarization axis of one type of linearly polarized light is rotated by 90° in the two separated light beams. °, set to be the same as the polarization axis of another linearly polarized light.

The polarized light conversion element array 500 is a device that separates the incident light beam into two types of linearly polarized light and emits it. As shown in FIG. shape.

The polarized light conversion element 510 includes: a plurality of polarized light separation films 511 arranged obliquely with respect to the incident light beam; reflective plates 512 arranged side by side between the polarized light separated films 511; Plate glass 513 is a translucent member arranged between films 512 .

The polarized light separation film 511 is composed of a dielectric multilayer film or the like whose Brewster angle is set to approximately 45°. This polarized light separation film 511 reflects, among the incident light beams, a light beam (S polarized light) which is one of linearly polarized light beams (S polarized light) having a polarization axis parallel to the incident surface of the polarized light separated film 511, so that it has The beam with the orthogonal polarization axis (P polarized light) passes through, and the incident beam is split into two kinds of linearly polarized beams.

The reflective film 512 is made of, for example, a single metal material having high reflectivity such as Al, Au, Ag, Cu, and Cr, or an alloy containing these multiple metals, and reflects S-polarized light reflected by the polarized light separation film 511 .

The plate glass 513 is a plate glass through which light beams pass, and is usually formed of white plate glass or the like.

Fig. 13 is a diagram for explaining the manufacture of the polarization conversion element array, and is a schematic diagram viewed from the thickness dimension direction.

Such a polarization conversion element 510 is manufactured, for example, in such a manner that polarization separation films 511 and reflection films 512 are alternately arranged at an angle of 45° to their front and back surfaces.

First, as shown in FIG. 13 , plate glass 513 with polarized light separation film 511 and reflective film 512 provided on both surfaces and plate glass 513 with nothing formed are bonded alternately with an adhesive. At this time, plate glass 514 on which no polarized light separation film and reflection film are formed is arranged on the upper and lower surfaces P, Q.

Next, as shown by the dotted line in FIG. 13 , it is cut approximately in parallel at predetermined intervals at an angle of approximately 45° to the front and back surfaces. Next, the portions protruding toward both end sides are cut along the cutting plane X to form a substantially rectangular parallelepiped plate shape. Finally, the polarization conversion element 510 is formed by polishing the entire surface including the cut surface X.

Accordingly, in the polarization conversion element 510 , the polarization separation film 511 and the reflection film 512 are arranged at equal intervals with an inclination of approximately 45° with respect to the light beam incident surface and the light beam exit end surface.

FIG. 14 is a schematic diagram of a part of the polarization conversion element main body 414B viewed from above.

The retardation plate 600 is a retardation plate that rotates the polarization axis of the P-polarized light passing through the polarization separation film 511 by 90°. As shown in FIG. 14 , the retardation plate 600 is attached at a position corresponding to the polarization separation film 511 when viewed along the direction of the illumination optical axis on the beam output end surface of the polarization conversion element 510 . At this time, the retardation plate 600 arranged on the illumination optical axis is attached across the two polarization conversion elements 510 .

As shown in FIG. 14 , the polarized light separation film 511 in each polarized light conversion element 510 is formed into a substantially "eight" shape in cross section, and is adjacent to each polarized light conversion element 510 on the adhering surface 500A. Between the adjacent polarized light separation films 511, an angle of approximately 90° is formed and a continuous state is formed. Therefore, in particular, a light beam having a strong brightness on the illumination optical axis emitted from the light source lamp 416 is irradiated onto the polarized light separation film 511 which is continuous at approximately 90°.

In FIG. 12 , the fixed frame 414A is configured as a metal frame member such as aluminum, and is formed in a substantially rectangular shape that holds the light beam incident end surface 810A of the polarization conversion element main body 414B.

In FIG. 12 , the fixing frame 414A includes: a contact surface 811 that contacts the beam incident end surface 810A of the polarization conversion element main body 414B; The left and right holding surfaces 812 are bent to prevent the polarization conversion element main body 414B from shifting in the left and right directions; Hold face 813 . These contact surfaces 811 , left and right holding surfaces 812 , and up and down holding surfaces 813 function as holding portions.

Fig. 15 is a perspective view of the above-mentioned fixing frame viewed from the light beam incident side.

The contact surface 811 is a rectangular plate-shaped portion having substantially the same dimensions as the outer dimensions of the polarization conversion element main body 414B. As shown in FIG. 15 , on the contact surface 811 , a rectangular opening 811A extending in the up-down direction is formed at approximately the center position, and on both sides of the opening 811A, each is spaced at approximately equal intervals. Two rectangular openings 811B are formed.

In FIG. 15 , the width W1 of the opening 811A is approximately twice the width W2 of the opening 811B, and part of the upper and lower corners at the opposite positions are not opened, and are formed to look like "ト" when viewed from the front. word shape.

The opening 811A is a substantially central portion of the polarization conversion element main body 414B, where the polarization separation film 511 connected at an angle of 90° is exposed on the light beam incident side (-Z direction). The opening 811B is a portion that exposes the polarization separation film 511 at another position on the light beam incident side (in the −Z direction).

In other words, as shown in FIGS. 12 and 15, on the contact surface 811, when viewed from the light beam incident side along the direction of the illumination optical axis, the reflective film 512 is blocked and the light beam from the above-mentioned light source lamp is blocked. Incident light shielding portion 414A1.

As shown in FIG. 12 , the vertical holding surface 813 is a portion that fixes the polarization conversion device 414 itself at a predetermined position of the lower light guide body 471 and prevents displacement in the vertical direction of the polarization conversion element main body 414B. The upper and lower holding surfaces 813 have an upper holding surface 814 formed at the upper end of the contact surface 811 and a lower holding surface 815 formed at the lower end of the contact surface 811 .

The upper holding surface 814 has a function of restricting the position so that the polarization conversion element main body 414B does not deviate upward. In addition, on the upper holding surface 814 , on both end edges thereof, projecting portions 816 projecting outward along the contact surface 811 are formed.

The lower holding surface 815 has a function of supporting the polarization conversion element main body 414B from the lower side. In addition, on the lower side holding surface 815 , there are formed extending portions 817 extending from both end edges thereof to the outside and the light beam emitting side along the contact surface 811 . One round hole opening 817A is formed in each of these extending portions 817 .

FIG. 16 is a perspective view showing how the polarization conversion device 414 is accommodated on the lower light guide body 471 . As shown in FIG. 16, inside the lower light guide body 471, at the position where the polarized light conversion device 414 is housed, a part is hidden in the screen, and two protrusions 475 on the left and right sides extending upward are formed to fit together as polarized light. The groove portion 476 of the protruding portion 816 of a part of the conversion device 414 .

The two protrusions 475 are parts inserted into the circular hole opening 817A of the extension part 817 when the polarization conversion device 414 is accommodated in the lower light guide body 471 . Accordingly, the movement of the lower end side of the polarization conversion device 414 is restricted.

The groove portion 476 is a portion that supports the fitted extension portion 816 from below, thereby restricting movement of the upper end side of the polarization conversion device 414 .

Therefore, in the fixing frame 414A, the circular hole opening 817A inserted by the two protrusions 475 and the protruding part 816 fitted into the groove part 476 have a fixing part for fixing on the lower light guide body 471. function.

FIG. 17 is a schematic diagram for explaining the function of the polarization conversion device 414 .

The light beams incident on the second lens array 413 are light beams having random polarization axes condensed by the small lenses, and enter a predetermined region of the polarization conversion device 414 . Furthermore, as described above, the light shielding portion 414A1 is formed on the fixed frame 414A, and shields the light beam that generates invalid polarized light among the light beams emitted from the second lens array 413 as shown by the dotted line in FIG. 17 .

The light beam incident on the polarization conversion device 414 is separated into P-polarized light and S-polarized light by the polarization separation film 511 . That is, the P-polarized light passes through the polarized light separation film 511, the S-polarized light is reflected by the polarized light separation film 511, and the optical path is converted by approximately 90°.

The S-polarized light reflected by the polarization separation film 511 is reflected by the reflection film 512 , the optical path is converted by approximately 90° again, and travels in approximately the same direction as the incident direction to the polarization conversion device 414 . In addition, the P-polarized light transmitted through the polarized light separation film 511 enters the retardation film 600 , the polarization axis is rotated by 90°, converted into S-polarized light, and emitted as S-polarized light. Therefore, the light beam emitted from the polarization conversion device 414 becomes substantially one kind of S-polarized light.

5. The effect of the implementation

According to the above-mentioned embodiment, the following effects are obtained.

(1) The polarization conversion element main body 414B is held by the adhesive agent from the contact surface 811, the left and right holding surfaces 812, and the upper and lower holding surfaces 813 constituting the fixed frame 414A, and the held things are stored in the lower light guide body 471, so The number of parts constituting the polarization conversion device 414 can be reduced from the conventional three parts to two, and the cost can be reduced. In addition, since the number of components is reduced to two in this way, only direct positional adjustment between these two components can be performed, so the position of the light shielding portion 414A1 relative to the polarization conversion element main body 414B can be adjusted with high precision. Therefore, it is possible to improve the shielding property of unnecessary light incident on the polarization conversion element 414B, and to further effectively utilize the light beam from the light source. Therefore, the projector 1 can also project a clear image with high brightness.

(2) Although it is a simple structure of inserting the protrusion 475 formed inside the lower light guide body 471 on the circular hole opening 817A formed in the extension part, the polarization conversion device 414 can be reliably fixed on the lower light guide body 471. on the guide body 471. Because of such a simple structure, it is possible to suppress the cost for the polarization conversion device 414 .

(3) Since the fixing frame 414A is made of metal, sufficient rigidity can be ensured even as a member holding the polarization conversion element main body 414B. In addition, since it is made of a metal such as aluminum with high thermal conductivity, heat generated in the polarization conversion element body 414B can be released to the outside, and thermal damage to the polarization conversion element body 414B having poor heat resistance can be prevented.

(4) In the polarization conversion element 510, since the polarization separation film 511 and the reflection film 512 are formed to be inclined at approximately 45° relative to the light beam incident direction, the generated and required linearly polarized light (S polarized light) will not be excessively increased. The inactive region of linearly polarized light (P-polarized light) whose polarization axis is different can be made under optimal conditions.

(5) Integrator illuminating optical system 41, owing to possess above-mentioned polarized light conversion device 414, thereby can convert the light beam emitted from light source device 411 into substantially a kind of linearly polarized light (S polarized light) and emit, can realize the effective of light beam. use.

(6) As described above, since the effective use of light beams is realized, the absorption of unnecessary light in the incident-side polarizing plate 442 arranged on the incident side of the liquid crystal panel 441 is reduced, and incident light caused by the absorption of the unnecessary light can be prevented. Thermal damage to the side polarizer 442.

6. Modifications of Embodiment

Furthermore, the present invention is not limited to the above-mentioned embodiments, but includes other configurations that can achieve the object of the present invention, and modifications such as those shown below are also included in the present invention.

For example, in the above-mentioned embodiment, the structure is such that the two protrusions 475 of the lower light guide 471 are inserted through the two circular hole openings 817A to fix the polarization conversion device 414, but the number of these circular hole openings 817A and the protrusions 475 Not limited to 2, no matter how many, as long as it can be fixed. In addition, the shape of the opening is not limited to a circle, and may be provided in a square shape, and the shape of the hole is not particularly limited.

In addition, in the above-mentioned embodiment, the fixing frame 414A is made of a metal material such as aluminum, but it is not limited thereto, and may be made of other materials such as resin, for example. In short, there are no particular limitations on the constituent materials as long as sufficient rigidity can be secured while maintaining the polarization conversion element main body 414B.

In addition, in each of the above-mentioned embodiments, the polarization conversion element 510 is laminated alternately with the plate glass 513 with the polarized light separation film 511 and the reflective film 512 formed on both surfaces and the plate glass 513 with nothing formed thereon. The plate glass 514 is laminated on the upper and lower surfaces to be cut and polished to manufacture, but the present invention is not limited thereto, as long as the polarized light separation films 511 and the reflective films 512 are alternately arranged. In this case, the angle of incidence with respect to the polarization separation film 511 and the reflection film 512 is not limited to 45°.

In addition, in the above-mentioned embodiment, only the example of the projector using three light modulation devices was given, but it can also be applied to a projector using only one light modulation device, a projector using two light modulation devices, or Projectors using more than 4 light modulation devices.

In addition, although a liquid crystal panel is used as the light modulation device, a light modulation device other than liquid crystal, such as a micromirror device, may be used.

Furthermore, in each of the above-described embodiments, a transmissive light modulation device having a different light-incident surface and a light-exit surface is used, but a reflection-type light modulation device having the same light-incident surface and light-exit surface may also be used.

Furthermore, in each of the above-mentioned embodiments, only examples of front-type projectors that project from the direction of viewing the screen have been given, but the present invention can also be applied to rear-type projectors that project from the direction opposite to the direction of viewing the screen. projector.

Claims (6)

1. polarized light converting means is characterized in that possessing:

The polarization main body, its formation comprises: relatively the incident beam tilted configuration, this incident beam is separated into a plurality of polarized light separation membranes of 2 kinds of rectilinearly polarized light light beams, a plurality of reflectance coatings of the rectilinearly polarized light light beam of any one party of alternately be configured in side by side between each polarized light separation membrane, reflection being separated by above-mentioned polarized light separation membrane, the transparent member of these polarized light separation membranes and reflectance coating is set, and a plurality of polarizers of polarizing axis of rectilinearly polarized light light beam that are arranged on light emitting side, the above-mentioned any the opposing party of conversion of this transparent member; And

Light-blocking member is set on the position not relative with the above-mentioned polarizer of the light beam light incident side of above-mentioned transparent member, blocks the incident of the light beam that penetrates from above-mentioned light source;

Wherein, this light-blocking member has the maintaining part of the end face that keeps above-mentioned polarization main body and is used to be installed to the optical element of taking in this polarized light converting means with the fixed part on the casing.

2. polarized light converting means according to claim 1 is characterized in that:

Said fixing portion is configured as the ora terminalis two ends from the above-mentioned maintaining part that contact with casing with above-mentioned optical element, the extension along the maintenance of above-mentioned maintaining part towards outside extension;

On this extension, be formed with and be formed on above-mentioned optical element and insert logical slotting general opening with the projection on the casing.

3. polarized light converting means according to claim 1 is characterized in that:

Above-mentioned light-blocking member is made of metal material.

4. polarized light converting means according to claim 1 is characterized in that:

Above-mentioned polarized light separation membrane and above-mentioned reflectance coating, the light beam incident direction tilts roughly 45 ° relatively, alternately arranges with the interval of regulation.

5. illumination optics device is characterized in that possessing:

Light source;

Light beam from light source is divided into the beam cutting element of many parts light beam; And

The polarized light converting means, have: the polarization main body, its formation comprises: relative incident beam tilted configuration, this incident beam is separated into a plurality of polarized light separation membranes of 2 kinds of rectilinearly polarized light light beams, alternately be configured between each polarized light separation membrane side by side, reflection is by a plurality of reflectance coatings of the rectilinearly polarized light light beam of any one party of above-mentioned polarized light separation membrane separation, the transparent member of these polarized light separation membranes and reflectance coating is set, and the light emitting side that is arranged on this transparent member, a plurality of polarizers of the polarizing axis of the above-mentioned any the opposing party's of conversion rectilinearly polarized light light beam; Light-blocking member is set on the position not relative with the above-mentioned polarizer of the light beam light incident side of above-mentioned transparent member, blocks the incident of the light beam that penetrates from above-mentioned light source; Wherein, this light-blocking member has the maintaining part of the end face that keeps above-mentioned polarization main body and is used to be installed to the optical element of taking in this polarized light converting means with the fixed part on the casing.

6. projector is characterized in that possessing:

Illumination optics device has:

Light source;

Light beam from light source is divided into the beam cutting element of many parts light beam;

The polarized light converting means, have: the polarization main body, its formation comprises: relative incident beam tilted configuration, this incident beam is separated into a plurality of polarized light separation membranes of 2 kinds of rectilinearly polarized light light beams, alternately be configured between each polarized light separation membrane side by side, reflection is by a plurality of reflectance coatings of the rectilinearly polarized light light beam of any one party of above-mentioned polarized light separation membrane separation, the transparent member of these polarized light separation membranes and reflectance coating is set, and the light emitting side that is arranged on this transparent member, a plurality of polarizers of the polarizing axis of the above-mentioned any the opposing party's of conversion rectilinearly polarized light light beam; Light-blocking member is set on the position not relative with the above-mentioned polarizer of the light beam light incident side of above-mentioned transparent member, blocks the incident of the light beam that penetrates from above-mentioned light source; Wherein, this light-blocking member has the maintaining part of the end face that keeps above-mentioned polarization main body and is used to be installed to the optical element of taking in this polarized light converting means with the fixed part on the casing;

Optic modulating device, the light beam that modulation is penetrated from this illumination optics device according to image information; And

Projecting optical device, enlarging projection is by the light beam of this optic modulating device modulation.

Images